1. Technical Field
The present invention relates generally to the monitoring of internal combustion engines and more particularly to a method for predicting the temperature of a catalyst in a catalytic converter in real time based on the operating conditions of the vehicle.
2. Discussion
Catalytic converters are used to reduce major air pollutants, such as hydrocarbons, carbon monoxide and oxides of nitrogen, contained in the exhaust gas from an internal combustion engine of a motor vehicle. Each converter contains catalysts that produce an exothermic chemical reaction that transforms noxious pollutants into carbon dioxide, nitrogen, and water vapor. The catalytic converter is integrated downstream from the vehicle's engine into the vehicle's exhaust system.
The effectiveness of reducing pollutants by a catalytic converter is highly dependent on the temperature and total gas throughput, which in turn depends on the operational states and conditions of the internal combustion engine. The ability to determine the temperature of the catalyst permits the use of various control strategies that may minimize emissions and/or protect the catalyst from exposure to excessive temperatures. Accordingly, it is necessary to determine the temperature of a catalyst in a catalytic converter in a reliable and accurate manner.